A 500 MHz solid-state NMR spectrometer is requested in order to replace an aging 360 MHz NMR instrument that was purchased in 1989. This NMR instrument currently supports four areas of NIH-funded biomedical research at Stony Brook University that rely on high resolution solid-state NMR for structure-function studies. The first project focuses on the structure and mechanism of G protein-coupled receptors (Steven Smith). These receptors are important pharmaceutical targets. Solid-state NMR methods are being used to determine the structures of the active state of the visual pigment rhodopsin, the 22- adrenergic receptor with bound agonists and antagonists, and CCR5 with bound HIV entry inhibitors. The second project (Erwin London) concerns membrane rafts and membrane domain formation. Integral membrane proteins and extrinsic membrane-associated proteins both associate with and may serve to nucleate cholesterol-rich domains. NMR structural studies are used in combination with fluorescence spectroscopy to understand the mechanism of domain formation and protein association. One structural target is the domain forming protein, caveolin. Caveolin is the protein component of caveolae, cholesterol-rich domains responsible for membrane internalization. The second project (Stuart McLaughlin) deals with the structure and function transmembrane and membrane-associated proteins having clusters of basic and aromatic residues. One structural target is the epidermal growth factor (EGF) receptor, a member of the ErbB family of receptor tyrosine kinases. The receptor tyrosine kinases are cell-surface membrane receptors that mediate cell growth and differentiation, and are associated with a wide variety of human tumors when constitutively activated through mutation or overexpression. NMR structural studies are focused on how receptor activity is regulated. The fourth project (William Van Nostrand) targets the structure, formation and inhibition of amyloid fibrils involved in Alzheimer's disease and cerebral amyloid angiopathy (CAA). Solid-state NMR is used to follow the structural changes of amyloid A2 peptides from monomers to oligomers to fibrils. The focus is on the A242 peptide and the Dutch and Iowa mutants of the A240 peptide. PUBLIC HEALTH RELEVANCE: Over the past ten years, solid-state NMR spectroscopy has emerged as an effective method for determining the high-resolution structures of cellular components that are not amenable to the traditional approaches in structural biology, namely X-ray crystallography and solution NMR spectroscopy. These structures include amyloid fibrils associated with a wide range of neurodegenerative diseases (Alzheimer's disease, Parkinson's disease, prion diseases) and G protein-coupled receptors, the major target of drugs currently on the market. The requested instrumentation supports research that focuses on these biomedical targets.